I disagree. I've done it and conversion is just fine.
I agree with you, Dave, but that seems like so much extra effort when you could just mash thinner in the first place.
Just presenting yet another option. I'm not saying that I do it a lot, but I've done it a couple times and it works. Of course these days I brew in a bag and skip the sparge altogether half the time. Doesn't get any easier than that. Crush like mad, mash as normal, pull the bag out, and roll.